Return BD values via ajax

Question

I have a screen where I must popular with database values using ajax.

When I click on the button to fill the fields the following error appears:

Failed to load Resource: the server responded with a status of 500 (Internal Server Error)

I don’t know what’s going on.

Model Code:

public class Client
{
    [Key]
    [MaxLength(128)]
    public string client_id { get; set; }

    [MaxLength(20)]
    public string client_cnpj { get; set; }

    [MaxLength(255)]
    public string client_companyname { get; set; }

    [Required]
    [MaxLength(255)]
    public string client_fantasyname { get; set; }

    [Required]
    [MaxLength(128)]
    public string client_namerepresentative { get; set; }

    [Required]
    [MaxLength(15)]
    public string client_cep { get; set; }

    [Required]
    [MaxLength(255)]
    public string client_street { get; set; }

    [Required]
    [MaxLength(10)]
    public string client_number { get; set; }

    [MaxLength(55)]
    public string client_complement { get; set; }

    [Required]
    [MaxLength(128)]
    public string client_neighborhood { get; set; }

    [Required]
    [MaxLength(128)]
    public string client_city { get; set; }

    [Required]
    [MaxLength(2)]
    public string client_uf { get; set; }

    [MaxLength(128)]
    public string client_email { get; set; }

    [MaxLength(15)]
    public string client_phone1 { get; set; }

    [MaxLength(15)]
    public string client_phone2 { get; set; }

    public int? client_currentcarrier { get; set; }

    public int? client_voice { get; set; }

    public int? client_web { get; set; }

    public int? client_renegotiation { get; set; }

    public DateTime? client_datevisitorcontact { get; set; }

    [Required]
    public string client_note { get; set; }

    public int? client_statusnegotiation { get; set; }

    [Required]
    [MaxLength(128)]
    public string client_company_id { get; set; }

    [MaxLength(128)]
    public string client_supervisingconsultant { get; set; }

    [MaxLength(128)]
    public string client_supervisingsalessupport { get; set; }

    [MaxLength(128)]
    public string client_consultant { get; set; }

    [MaxLength(128)]
    public string client_salessupport { get; set; }

    [MaxLength(128)]
    public string client_source { get; set; }

    public bool client_return { get; set; }

    public bool client_sendemail { get; set; }

    public DateTime client_dateregister { get; set; }

    [ForeignKey("client_company_id")]
    public virtual Company Company { get; set; }

    public virtual ICollection<HistoricFunnel> HistoricFunnel { get; set; }

    public virtual ICollection<ActivityClient> ActivityClient { get; set; }
}

Controller Code:

[HttpPost]
public JsonResult ReturnVisit(string id)
{
    var visit = _clientAppService.GetById(id);
    return Json(new { visit = visit });
}

Javascript code:

$(".visits-table tr a").click(function () {
    var id = $(this).parent().parent().attr("id");

    $.ajax({
        dataType: "json",
        type: "POST",
        url: "/Visits/ReturnVisit",
        data: { id: id },
        success: function (data) {
            alert("entrou")
            alert(data)
        }
    });

    return false;
});

Answer 1

Error 500 is a generic HTTP error, you don’t know what’s going on. You need to read the page with the result of the request. Also, if your IIS is not configured to show errors it will not solve. Try setting up IIS to turn off "customErrors" by configuring it on Web.onfig

<system.web>
    <customErrors mode="Off"></customErrors>
</system.web>

Then run your error code and check exactly what error is occurring. If you’re using it to debug Firefox, use Firebug and see the Request Ajax result in the Console tab. Chrome is the same thing. To enter this console press F12.

Another thing, you seem to be trying to return a "visit" domain class. You should never expose a domain class, always turn your domain class into a Viewmodel class (POCO). This avoids cyclic reference and other problems when exposing a domain class.

Answer 2

Try to do it by GET

$(".visits-table tr a").click(function () {
var id = $(this).parent().parent().attr("id");

$.ajax({
    dataType: "json",
    type: "GET",
    url: "/Visits/ReturnVisit",
    data: { id: id },
    success: function (data) {
        alert("entrou");
        alert(data);
    }
});

return false;

});

public JsonResult ReturnVisit(string id)
{
    var visit = _clientAppService.GetAll();
    return Json(visit,JsonRequestBehavior.AllowGet);
}

Answer 3

Depending on your application’s IIS post, put the URL directly to controller/action may not be legal. Use the power of razor.

$(".visits-table tr a").click(function () {
    var id = $(this).parent().parent().attr("id");

    $.ajax({
        dataType: "json",
        type: "POST",
        url: '@Url.Action("ReturnVisit", "Visits")',
        data: { id: id }
        success: function (data) {
            alert("entrou")
            alert(data)
        }
    });

    return false;
});

Take care of requests... if the controller method is noted as [HttpGet] you must make a request GET. If you’re like [HttpPost] you must make a request POST.

Your controller

[HttpPost]
public JsonResult ReturnVisit(string id)
{
    var visit = _clientAppService.GetAll();
    return new JsonResult { Data = visit };
}

Your model has to be [Serializable]:

using System;

[Serializable]
public class Client
{

....

}

Every property that is a Class, that class has to be serialized as well.

More about the serialization